Now edit the file using your favorite text editor and enable the appropriate repository ([ol6_u1_base] in our case) by changing the value of the enabled variable from 0 to 1.

Now you can run yum list all to get a full list of all available packages. You can install them by running yum install <packagename>

However, being a distribution with a focus on the enterprise and data center, the package selection is limited to this scope. If you are looking for additional packages, you would have to either compile them from source or download pre-built binaries from an external package repository.

Enter EPEL, the "Extra Packages for Enterprise Linux" repository. According to their extensive FAQ, EPEL "is a volunteer-based community effort from the Fedora project to create a repository of high-quality add-on packages that complement the Fedora-based Red Hat Enterprise Linux (RHEL) and its compatible spinoffs, such as CentOS and Scientific Linux.".

Oracle Linux is based on RHEL, too, and is 100% userland-compatible with it. Therefore any package available from EPEL will install and run just fine, giving you access to a large pool of additional software. However, please keep in mind that this software is not covered by any Oracle Linux Support agreement you may have!

You can add and enable the EPEL repository by performing the following steps (as the root user):

Download and install the repository package which includes the appropriate repository information for your version of Oracle Linux: